Combination resistor



,Mall'l 13, 1934- J. L. MCWEENY 1,950,508

COMBINATION RESISTOR Filed April 13. 1931 Patented Mar.. 13, 1934 UNITEDSTATES COMBINATION RESISTOR John L. McWeeny, Chicago, 111-., assignor,by mesne assignments, to The Muter (Jompany,7 Chicago, Ill., acorporation o! Illinois Application April 13,

2 claims.

My invention relates to resistors and more particularly to a novel formof combination inductive and non-inductive resistor comprising singlemechanical unit.

It is well known that in the building of radio equipment and otherelectrical devices of a similar nature, a large number of resistancesare necessary in different phases of the various circuits therein. Ithas. been the common practice to provide a single resistor for eachresistance required, and to dispose the same on the chassis at the mostdesirable point from the standpoint of assembling efficiency. It isobvious therefore, that in a radio of complicated construction, arelatively large number of such resistors may be necessary, and beingdisposed at various points about the chassis tend to increase both thecost of the device and cost of assembling due to the labor involved inattaching and soldering each individual resistor in its proper place.

It has also been found desirable in many instances, to provide both theinductive or wire wound type of resistor and also the. non-inductiveorcarbon type resistor in the same assembly. This for the reason that itis mechanically7 impractical to eflciently manufacture an accurateresistor of the non-inductive type below, for example, three or fourthousand ohms resistance. Where a lower resistance is desired, theinductive or wire wound type is often found desirable, and suchresistors can be manufactured as low as several hundredths of an ohmresistance. In. many instances where an accurate resistance of overthree or four thousand ohms is desired, the carbon type` is preferredbecause of the possibility of obtaining the greatest amount ofresistance in the minimum of space.

In addition, it is well known in the trade that a wire wound orinductive type of resistor is capable of carrying several times morecurrent than the carbon type of same cross section without ythe dangerof overloading and consequent burning out. It is evident therefore, thatin the assembly of thel common radio apparatus of today, a large numberof factors must beV considered, involving the usekof several sizes ofboth inductive and non-inductive resistors, and among the inductiveresistors, a number of y sizes of wire in as many resistors is desirableto 193'1, serial No. 529,574

It is a further object of my invention to pro vide a construction ofthese two types of resistances which permits the manufacture andpreparation of the separate units in large numbers, and later insertingthem within a unit of several resistances according to the amount ofohmage desired, or according to the wattage it is desired to dissipate.In this manner the various resistances utilized in a combination unitcan be each individually pre-tested, .and when the final product istested for accuracy, it will be found to come Within the limits of plusor minus allowed by the specifications, and it will not be necessary toreject the combination unit simply because one of the resistances isinaccurate, as is at present frequently the case.

My invention will be more readily understood by reference to theaccompanying drawing, in which:

Fig. 1 is a top plan view of a combination resistance unit constructedin accordance with my invention;

Fig. 2 is a side elevation thereof, showing the metal housing insection;

Fig. 3 is a vertical sectional view taken on the lines 3 3 of Fig. 2after unit has been enclosed.

Fig. 4 is a perspective view of the one-piece metal terminal clip of myinvention, and

Eig. 5 is a perspective view of the spring clip' applied to theresistance units.

By reference to the drawing it will be seen that the combination unit ofmy invention comprises a plurality of pre-formed and pre-testedresistance units 10, 11, 12 and 13` placed in an end to end relationwithin an insulating jacket 14, which fits within a metal housing 15,having the fingers 16 formed on the ends thereof, which may be bent andinserted within apertures in a chassis, if desired. I may also prefer toprovide the vapertures 16a in the ends to permit rivets or bolts to beinserted. As shown in Fig. 1 the resistances 10, 11, 12 and 13 are madeup of alternate individual pre-formed units of the carbon ornon-inductive ty-pe and the wire wound or inductive type for thepurposes desired within any particularly electrical circuit. Thenon-inductive resistance units are formed in the manner describedandclaimed in my co-pending application, Serial No. 529,573,

led April 13, 1931, as best shown in Fig. 3.-

These units, indicated by 10 and 12 in Fig. 1 are formed over anon-conducting base 17 h aving one face ground to a true plane surfaceand having the resistance material 18 applied thereon.

Thereafter the spring clip 19, best shown in Fig. 5 is applied thereoverat desired intervals. Thereafter the carbon unit so formed is treatedwith a moisture resisting fluid 20 which is later removed from the faceof the clips 19 to provide for electrical contact with the terminalclips generally indicated by 20.

The terminal clips, as best shown in Fig. 4 are formed of a singlelength of metal, having an upstanding terminal portion 21 and arms 22and 23, formed at right angles thereto at a suitable distance from theend thereof. The arm 23 is formed out of the material of the arm 22. Inthe initial bent position the extremities 24, 25 of the arms 22 and 23are intended to lie substantially parallel to each other and in the sameplane with the upstanding portion 21. When the terminal clip 20 isapplied to the treated base 16 having the spring clip 18 thereon, theextremity 24 of the longer arm is intended to be bent over the other tolie on the 'opposite face of the unit and substantially parallel to thearms 22, 23. Likewise the extremity 25 is adapted to be rebent and tosubstantially intert with the cut out portion 26. Thus in a single stripof material I have provided an extremely eicient contacting clip whichis readily applied and when closed is practically immovable on the unit.

After the application of the terminal clips 20, the unit is set into anon-conducting jacket 14 and metal housing 15 having the screw or rivetapertures 15a, which is thereafter closed, as shown in Fig. 3. The nalopeiation consists in spraying or dipping the unit in another bath 27 ofmoisture resisting material which serves not only to exclude themoisture, but also in keeping outforeign matter that may seek entrancethrough the top or ends of the unit.

The inductive units l1 and 13 may be formed in any one of the severalmanners depending upon the purpose of the units within the circuits. Theinductive resistances may be formed of similar or different sizes ofresistance Wire, depending on the resistance desired within a givenlength of material or, they may be wound with a different number ofturns per inchof a particular size of wire. If desired, the spring clips19 may be applied to the inductive types, thus serving as a guide forpositioning of the terminal clips 20 and to avoid the necessity offurther testing of the particular unit. It is Well known that due to alarge number of circumstances, involving the dimensions of the base orcross section and chemical makeup of the wire, the units must.necessarily be individually tested regardless of the use of a templatein positioning the contacting clips. If desired, the terminal clips 20may be applied directly to the wire without the use of the spring clip19, in which event I prefer to utilize an apparatus disclosed in mycopending application, Serial No. 519,382, filed March 2, 1931 whichissued as Patent 1,870,462, Aug. 9, 1932.

It is obvious from the foregoing description that by means of the use ofinductive and noninductive resistance units within a single housing, andby application of terminal clips at suitably spaced intervals onindividual units, a large number of resistances may be had Within asingle, central housing, being readily1 accessible for adjustment orrepair, as well as Ainsuring the utmost economy in the original assemblyof the electrical device. It is obvious also that by means of theconstruction hereindescribcd, the various resistances incorporated inthe device may be manufactured in large numbers and tested to aparticular value of resistance, and the combination unit as hereindescribed can be assembled readily by the mere use of the preformed andpre-tested individual units, rather than the necessity of forming eachof the resistances desired for a particular unit in the nature of atailor made unit.

A number of modifications and variations in the device herein describedwill doubtless occur to those skilled in the art, and I do not Wish tobe limited except as indicated in the appended claims.

I claim: .1. A resistor unit of the class described com prising aninductive resistance including a at strip of insulating material, alength of resistance Wire wound thereabout, and terminal clips securedto said winding of wire at selected intervals, a non-inductiveresistance including a second fiat strip of insulating material shapedsimilarly to the first named strip and having a plane surface to receiveresistance material, an electrical resistance material disposed oversuch plane surface of said second strip, a coating of moisture resistingmaterial over such material and the second strip, and terminal clips onsaid strip and connected electrically to said resistor material atselected spaced intervals longitudinally of said strip, a thin sheet ofinsulatory material folded longitudinally to form a closure for saidstrips, the ends of said sheet overlapping and having a longitudinalopening therebetween, and a housing of highly conductive metal shapedabout said strips, clips, and sheet, said housing having a longitudinalopening, said rst and second strips being disposed in spaced end to endrelationship within said folded insulatory sheet with the ends of saidterminals projecting from the longitudinal opening thereof, said metalhousing being disposed over said folded body with the longitudinalopening therein coinciding with the longitudinal opening in said sheetand clamping said strips, said clips and said sheet in assembly.

2. A resistor unit of the class described comprising one or moreinductive resistances each including a flat strip of insulatingmaterial, a length of resistance wire wound thereabout, and terminalclips secured to said winding of wire at selected intervals, and one ormore non-inductive resistances each including a second flat strip ofinsulating material shaped similarly to the first named strip or strips,electrical resistance material upon the second strip or strips, acoating of moisture resisting material over such material and the secondstrip or strips, and terminal clips on said strip or strips andconnected electrically to said resistor material at selected spaceintervals longitudinally of said strip or strips, a thin sheet ofinsulatory material folded longitudinali. to form a closure for saidstrips, the ends of said sheet overlapping and lhaving a longitudinalopening therebetween, and a housing of highly conductive material aboutsaid strips, clips and sheet, said housing having a longitudinalopening, said first named and second named strips being disposed inspaced end to end relationship Within said folded insulatory sheet withthe ends of said terminals projecting from the longitudinal openingthereof,

said metal housing being disposed over said folded body with thelongitudinal opening therein coinciding with the longitudinal opening insaid sheet and clamping said strips, said clips and said sheet inassembly.

JOHN L. McWEENY.

